Clear thermoplastic multi-ply meat tray and absorbent strips

ABSTRACT

A clear, plastic tray, and a method for the production thereof, intended for the packaging of food products, such as meats, and the like, where the package contents will be clearly visible. The tray is completely transparent and is produced from sheet material which includes a preinserted strip or plurality of strips of absorbent cellulosic material for the reception and retention of any fluid or fluids which may drain from the package contents subsequent to the packaging.

United States Patent 1,865,742 7/1932 Chapman inventor John J.Quackenbush Monroe, Conn.

Appl. No. 795,141

Filed Jan. 27, 1969 Patented May 25, 1971 Assignee National Distillersand Chemical Corporation New York, N.Y.

CLEAR THERMOPLASTIC MULTI-PLY MEAT TRAY AND ABSORBENT STRIPS 8 Claims, 6Drawing Figs.

Int. Cl 865d 7/42 Field of Search 220/83- References Cited UNITED STATESPATENTS 2,719,804 10/1955 Carlson 156/178X 3,026,209 3/1962 Niblack etal... 99/174 3,040,947 6/1962 Wells et al. 229/2.5 3,155,303 11/1964Fenkel 229/25 3,444,024 5/1969 Hillas 156/178 Primary Examiner-Joseph R.Leclair Assistant Examiner-James R. Garrett Attorney-Allen A. Meyer,.lr.

packaging.

- PATENTEDMAY25I97I 3580.413

, SHEET 1 OF 2 INVENTOR F I G. 3 JOHN J. QUACKENBUSH' ATTORNEY PATENTEI]HAYZSlHYI 3580.413

SHEET 2 OF 2 INVENTOR F l 6 JOHN J. QUACKENBUSH ATTORNEY CLEARTHERMOPLASTIC MULTI-PLY MEAT TRAY AND ABSORBENT STRIPS This inventionrelates to plastic trays for the packaging of food products, and thelike, and more particularly to such a tray produced from transparentmaterial and having see through characteristics whereby the top andbottom surfaces of the contents, as well as the side or edge surfaces,will be subject to inspection by the prospective purchaser.

It is known in the art to produce trays of the character with which wehere are concerned from such materials as polyethylene, polypropylene,polystyrene, polyvinyl chloride, and the like. Such trays are widelyused and, for many purposes, are highly satisfactory. However, where thepackage contents are of such a nature that drainage occurs within thepackage, trays of this character become highly unsatisfactory sincecertain products, and meats in particular, discolor rapidly when incontact with the tray surface and often deteriorate to the point ofspoilage.

This situation is further aggravated by drainage or exudate from theproduct, whether blood or bloody colored water, which flows to the edgesof the tray and is not only unsightly but also is repelling to theprospective purchasers.

It is known to place a sheet of absorbent material in the tray locatedimmediately beneath the contents. Such sheet material will, of course,absorb drainage. However, at the same time, the rate and degree ofdrainage is accelerated to the detriment of the packaged product byreason of capillary attraction. Further, such sheet material preventsinspection by the prospective purchaser of the bottom surface of thepackage contents and, with a view to consumer protection, laws are beingformulated and have been adopted in certain states requiring that nomore than percent of the surface area on the top or bottom surfaces ofthe contents may be obscured as by packaging materials and label.

It is a major purpose of the present invention to produce a transparentplastic tray of the class set forth having novel means for theabsorption of drainage from the product contained therein, while at thesame time providing substantially complete visibility of the packagecontents.

It is a further object of the invention to provide an improved plastictray for the packaging of food products, particular consideration beinggiven to such products as meat, poultry, and the like, which exudemoisture, the novel package maintaining a clean fresh, and wholesomeappearance even when a substantial amount of exudate is present therein.

It is a still further object of the present invention to provide a novelclear plastic tray of the class set forth which will have meansincroporated therein for the absorption and retention of exudateoccurring within the package thereby preventing the dispersion thereofto the serious detriment to the appearance and quality of the packagedproducts.

It is a still further object of the invention to provide a novel methodfor the production of clear plastic sheet wrapping materials, for thepackaging of food products or from which plastic fully transparent traysmay be produced, said sheet wrapping material having incorporatedtherewith relatively narrow strips of cellulosic and absorbent materialfor the reception and retention of any exudate from the packagecontents.

Further objects and advantages of the invention will be readily apparentfrom the following description, taken in conjunction with theaccompanying drawings, wherein:

FIG. 1 is a perspective view illustrating, somewhat diagrammatically,extrusion apparatus for the production of transparent plastic sheetmaterial having imbedded therein, simultaneously with the extrusionoperation, spaced strips of absorbent cellulosic material, such wrappingmaterial being highly suitable for the packaging of food products or foruse in the direct molding of clear plastic trays of the class with whichwe here are concerned;

FIG. 2 is a fragmentary sectional view, on a substantially enlargedscale, through laminated plastic sheet wrapping material produced inaccordance with the present invention;

FIG. 3 is a detail sectional view illustrating, somewhatdiagrammatically, molding apparatus for the production of a clearplastic tray from sheet material produced in accordance with the presentinvention;

FIG. 4 is a perspective of a molded clear plastic tray produced by theapparatus of FIG. 3;

FIG. 5 is a transverse sectional view taken on the line 5-5 of FIG.'4;and

FIG. 6 is a longitudinal sectional view through the plastic tray of FIG.5, taken on the line 6-6, and illustrating (conventionally) a foodproduct contained within the tray and an overwrap of suitablethermoplastic material to provide a finished and sealed package.

As shown in the drawings, particular reference being had to FIG. 1thereof, the extruder 10 delivers molten plastic material such aspolyethylene, polypropylene, polystyrene, polyvinyl chloride, or othersuitable olefin, directly to the die 11 which has an elongated andnarrow discharge orifice through which the molten plastic material exitsin sheet form as indicated at 12.

The thickness of the sheet 12 may vary through an extremely large range,in accordance with the width of the orifice and the required end use.Where the production of plastic trays is contemplated, the sheet mayrange in gauge from 20 mils to mils. Further, laminar extrusiontechniques may be employed, as is known in the art, whereby the extrudedsheet may be constituted by more than a single layer and such layers maybe of similar or dissimilar plastic materials. Thus, it would be asimple matter to laminate a sheet having, for example, one layer ofpolyethylene and another layer of polypropylene, or a sheet having alayer of one plastic material sandwiched between two layers of adissimilar material. Such combinations are known and are utilized tomeet desired requirements as to strength, transparency, gloss, and thelike.

A plurality of spaced rolls 13 of relatively thin strips of cellulosicmaterial 14 are located adjacent the die 11 and are mounted in anydesired manner whereby the extremities of the strips 14 will bepresented to the extruded sheet 12 as it leaves the die orifice insubstantially molten condition. A casting roll 15 is mounted adjacentthe die orifice and substantially in the path of the extruded sheet 12,the distance between the casting roll 15 and the die orifice beingsufficiently great that the extruded sheet 12, carrying therewith theextremities of the strips 14, will have cooled at ambient temperature toselfsustaining condition.

The sheet 12 is then drawn beneath the casting roll 15 which, desirably,is furnished with a highly polished chrome surface to provide anappropriate finish, having requisite characteristics as to gloss, etc.,on the material being produced. Simultaneously with the sheet 12contacting the casting roll, the cellulosic strips 14 are embeddedwithin the upper surface of the sheet, which has not yet fullysolidified, as is indicated more clearly in FIGS. 2 and 5 of thedrawings, and the finished wrapping material thus produced is carried toa wind-up roll 16 or other suitable storage facility.

The sheet 12 may be laminar and include an outer layer 12a of a similaror dissimilar polyolefin. Thus, the inner layer with the cellulosicinserts might be produced from polypropylene having increased ruptureresistant characteristics while the outer layer might be polyethylenethereby providing greater flexibility and heat sealing characteristics.The material thus described is highly suitable for wrapping andpackaging and, if desired, may be fabricated into bags with particularfacility. Thickness may vary through a wide range. It has been found inpractice that the thickness of the cellulosic strips may beapproximately 50 percent of the sheet material. Thus, for example, thecellulosic strips may have a thickness of approximately 5 mils in sheetmaterial which is 10 mils thick. For highly satisfactory molded trays,an outer layer approximately 20 mils in thickness may be employed.

Such material may be molded into trays having maximum rigidity andnesting characteristics and appropriate molding apparatus has beenillustrated conventionally in FIG. 3 of the drawing. As shown, the moldincludes a female base portion 17 and a male upper portion 18 which mateto produce a rigid tray 20 having a bottom wall 21, outwardly inclinedsidewalls 22, and a marginal edge or bead 23. Spaced cellulosic strips24 are imbedded in the upper surface of the bottom wall 21 and,desirably, a plurality of grooves or channels are provided to uniformlylead any exudate from the package contents directly to the absorbentstrips 24.

As shown more clearly in FIG. 4 of the drawings, the grooves or channels25 may provide an ornamental, effect, with spaced, slightly raisedsurfaces 21a therebetween, each extremity of the centrally locatedgrooves or channels 25 leading directly to an absorbent strip 24 whilethe outermost of said grooves or channels may be angularly inclined asillustrated at 25a to prevent any accumulation of exudate at themarginal edges of the tray.

Simple molding techniques, under appropriate conditions of elevatedtemperature and pressure, are all that are required to produce rigidtrays, as illustrated and described, with particular economy. Ifdesired, the surfaces 210 may be elevated slightly above the uppersurfaces of the cellulosic absorbent strips 24 thereby avoiding directcapillary drainage thereto of exudate.

As illustrated in FIG. 6 of the drawing an overwrap may be provided,produced from transparent readily heat-sealable and moisture-impervioussheet material such as polyethylene, or the like, to produce acompletely sealed and highly attractive finished product havingsubstantially complete visibility of packaged contents illustratedconventionally as at P.

There has thus been described a novel, transparent packaging materialwhich is particularly suitable for the packaging of food products, suchas meat, or the like, where control or prevention of moisture build upis of particular importance. The interior surface of this packagingmaterial, which may be fabricated or molded into rigid receptacles ofany desired configuration such as trays and the like having see-throughcharacteristics, includes a plurality of spaced, pressed-in strips ofabsorbent eellulosic material, the number, thickness, and width of suchstrips having direct relationship to the size and nature of the packagedproduct, for the absorption of a substantially large percentage ofnatural juices, or liquids, which may exude from the package contents,

It will be obvious to those skilled in the art that various changes maybe made in the invention without departing from the spirit and scopethereof and reference is had to the claims for summaries of theessentials of the invention and novel features of construction, for allof which protection is desired.

I claim: I

1. A plastic receptacle for holding a moisture-containing food productsuch as meat or the like, said receptacle including a bottom walltherefrom, the upper surface of said bottom wall including a pluralityof spaced, absorbent cellulosic strips imbedded therein and extendingcontinuously across said upper surface and upwardly across the innersurface of the two adjacent sidewalls of said receptacle, and aplurality of spaced channels in said upper surface, providingcommunication between adjacent spaced cellulosic strips.

2. The receptacle of claim 1, wherein the plastic material from whichthe receptacle is fabricated is transparent.

3. The receptacle of claim 2, wherein the total area of the cellulosicstrips is no more than 10 percent of the area of the side and bottomwalls of the receptacle.

4. The plastic receptacle of claim 1, wherein the material from whichthe receptacle is fabricated is a laminate of an upper layer ofpolypropylene and a lower layer of polyethylene.

5. The receptacle of claim 1, wherein the upper surface of the bottomwall is raised above the upper surface of the absorbent cellulosicstrips.

6. A transparent plastic tray comprising a bottom wall and foursidewalls extending upwardly therefrom, the upper surface of said bottomwall including a plurality of substantially parallel, spaced, absorbentcellulosic strips lmbedded therein and extending continuously acrosssaid upper surface and upwardly across the inner surface of the twosidewalls which are transverse the direction of said strips and aplurality of spaced channels in said upper surface providingcommunication between adjacent cellulosic strips.

7. The tray of claim 6 wherein the cellulosic strips are narrow so as toprovide substantially complete visibility of a food product heldthereon.

8. The tray of claim 6 wherein the plastic portion comprises a laminateof an upper layer of polypropylene and a lower layer of polyethylene.

and sidewalls extending upwardly

2. The receptacle of claim 1, wherein the plastic material from whichthe receptacle is fabricated is transparent.
 3. The receptacle of claim2, wherein the total area of the cellulosic strips is no more than 10percent of the area of the side and bottom walls of the receptacle. 4.The plastic receptacle of claim 1, wherein the material from which thereceptacle is fabricated is a laminate of an upper layer ofpolypropylene and a lower layer of polyethylene.
 5. The receptacle ofclaim 1, wherein the upper surface of the bottom wall is raised abovethe upper surface of the absorbent cellulosic strips.
 6. A transparentplastic tray comprising a bottom wall and four sidewalls extendingupwardly therefrom, the upper surface of said bottom wall including aplurality of substantially parallel, spaced, absorbent cellulosic stripsimbedded therein and extending continuously across said upper surfaceand upwardly across the inner surface of the two sidewalls which aretransverse the direction of said strips and a plurality of spacedchannels in said upper surface providing communication between adjacentcellulosic strips.
 7. The tray of claim 6 wherein the cellulosic stripsare narrow so as to provide substantially complete visibility of a foodproduct held thereon.
 8. The tray of claim 6 wherein the plastic portioncomprises a laminate of an upper layer of polypropylene and a lowerlayer of polyethylene.